On my last Carnival Cruise (Liberty Dec 27) there was a guy signing people up for a Carnival Visa or Master Charge credit card where you can earn miles or points towards future cruises. My airline miles card seems to never have space when I want to use it. Has anyone used this card and received a free or greatly reduced cruise where you felt using the card was worth it?

Thanks, I read the beginning of that thread but didn't see anything regarding the Carnival Credit Card. But reading further it turned into a thread about the credit card. So thanks for steering me in that direction.